Axsis Consultants Limited
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Security Reviews
Many organisations appreciate the need to put in place appropriate security
policies and countermeasures, but may not have had the resources to give it
a high priority.
Often the trigger to take some action is a major upgrade of office automation
and network infrastructure linking most buildings and staff, since the threats
and vulnerabilities increase with inter-linked systems and more widespread
user access. This applies even more so if external dial in access or mail
gateways are required, let alone Internet access.
This paper discusses some of the considerations that apply in
developing an appropriate response. It can be used to assess the priorities
for a relatively simple and quick review.
Scope
There is much emphasis in security studies on defining the scope of the "System"
being covered, and who the users are. Possibilities include:
- The organisation as a whole, including paper based systems and procedures,
- IT systems, considering all information accessed, stored or transmitted
electronically,
- The office automation and network infrastructure,
- Specific application systems, such as the finance system,
- External network and remote access (dial up) interfaces, including gateways
and firewalls.
Deliverables
Depending on the scope, and assuming a focus on IT, the deliverables may
include one or more of:
- IT Security Policy , defining in a short high level document
the general principles to be followed, plus both management and user or
staff responsibilities for the implementation and maintenance of security.
- Security Review Report , summarising the findings and
recommendations of an informal review.
- Security Risk Assessment , for instance following UK
government guidelines.
- System Security Policies (SSPs) for each system, where
the office automation and network infrastructure could be one system and
the finance system another. These could follow a formal structure such as
that of the UK government guidelines, and consider global, local and electronic
security environments. Counter measures are specified with regard access
and access control, authentication, accounting and auditing, availability
and integrity.
- CRAMM® Report , following use of the CRAMM software
tool as described below.
- Security Operating Procedures (SyOPs) , defining security
responsibilities and administrative procedures for various classes of staff
such as system administrators and users.
Related Areas
Related areas sometimes considered along with data security include:
- Availability Requirements for day to day operation, if not specified in
a Service Level Agreement.
- An Availability and Resilience Review is sometimes appropriate, if not
already covered.
- Disaster Recovery and Contingency Planning may also be a business requirement.
Approach
Once the scope and deliverables have been agreed a plan can be drawn up such
as:
- Stage 1 - Prepare through consultation within the organisation an assessment
of the nature of information held and transferred electronically, including
for CRAMM (see below) asset valuation and the impact of disclosure, destruction,
modification or unavailability of data.
- Stage 2 - Threat (likelihood) and vulnerability (exposure) assessments.
- Stage 3 - Security design and risk management proposals, including recommended
countermeasures.
- Stage 4 - Finalisation and presentation of the agreed deliverables, such
as an SSP or a Security Review report.
A formal CRAMM approach can be followed to ensure a thorough consideration
of all relevant factors. It requires more extensive consultation within the
organisation, more formal consideration of threats and vulnerabilities and
more extensive consideration of countermeasures. It also produces voluminous
reports, which require interpretation before an appropriate policy can be
derived and presented to management.
A CRAMM review as such can only be carried out utilising the UK Government
sponsored CRAMM tool for the analysis and management of IT security risks.
AXSIS Experience
We have advised many commercial concerns and UK Government departments on
office systems and network infrastructure security matters for protectively
marked information, including the preparation of approved SSPs. References
are available on request. This work included liaising with the appropriate
authorities, and advising departments on the use of e-mail gateways, remote
access and the feasibility of Internet connection.
Please contact us if you would like
to discuss what might be appropriate for your organisation, without any obligation,
see our Web security site list
or see below for further information.